All, > -----Original Message----- > From: Neil Zhang [mailto:[email protected]] > Sent: 2012年12月28日 18:00 > To: [email protected]; [email protected] > Cc: [email protected]; Neil Zhang; [email protected] > Subject: [PATCH] sched: remove redundant update_runtime notifier > > migration_call() will do all the things that update_runtime() does. > So it seems update_runtime() is a redundant notifier, remove it. > > Furthermore, there is potential risk that the current code will catch BUG_ON > at line 687 of rt.c when do cpu hotplug while there are realtime threads > running because of enable runtime twice. > > Cc: [email protected] > Signed-off-by: Neil Zhang <[email protected]> > --- > kernel/sched/core.c | 3 --- > kernel/sched/rt.c | 40 ---------------------------------------- > kernel/sched/sched.h | 1 - > 3 files changed, 0 insertions(+), 44 deletions(-) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c index > 257002c..7b6a4d8 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -6779,9 +6779,6 @@ void __init sched_init_smp(void) > hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE); > hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE); > > - /* RT runtime code needs to handle some hotplug events */ > - hotcpu_notifier(update_runtime, 0); > - > init_hrtick(); > > /* Move init over to a non-isolated CPU */ diff --git > a/kernel/sched/rt.c > b/kernel/sched/rt.c index 418feb0..1a499d2 100644 > --- a/kernel/sched/rt.c > +++ b/kernel/sched/rt.c > @@ -697,15 +697,6 @@ balanced: > } > } > > -static void disable_runtime(struct rq *rq) -{ > - unsigned long flags; > - > - raw_spin_lock_irqsave(&rq->lock, flags); > - __disable_runtime(rq); > - raw_spin_unlock_irqrestore(&rq->lock, flags); > -} > - > static void __enable_runtime(struct rq *rq) { > rt_rq_iter_t iter; > @@ -730,37 +721,6 @@ static void __enable_runtime(struct rq *rq) > } > } > > -static void enable_runtime(struct rq *rq) -{ > - unsigned long flags; > - > - raw_spin_lock_irqsave(&rq->lock, flags); > - __enable_runtime(rq); > - raw_spin_unlock_irqrestore(&rq->lock, flags); > -} > - > -int update_runtime(struct notifier_block *nfb, unsigned long action, void > *hcpu) -{ > - int cpu = (int)(long)hcpu; > - > - switch (action) { > - case CPU_DOWN_PREPARE: > - case CPU_DOWN_PREPARE_FROZEN: > - disable_runtime(cpu_rq(cpu)); > - return NOTIFY_OK; > - > - case CPU_DOWN_FAILED: > - case CPU_DOWN_FAILED_FROZEN: > - case CPU_ONLINE: > - case CPU_ONLINE_FROZEN: > - enable_runtime(cpu_rq(cpu)); > - return NOTIFY_OK; > - > - default: > - return NOTIFY_DONE; > - } > -} > - > static int balance_runtime(struct rt_rq *rt_rq) { > int more = 0; > diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index > fc88644..16d18a1 100644 > --- a/kernel/sched/sched.h > +++ b/kernel/sched/sched.h > @@ -890,7 +890,6 @@ extern void sysrq_sched_debug_show(void); > extern void sched_init_granularity(void); extern void > update_max_interval(void); extern void update_group_power(struct > sched_domain *sd, int cpu); -extern int update_runtime(struct notifier_block > *nfb, unsigned long action, void *hcpu); extern void > init_sched_rt_class(void); extern void init_sched_fair_class(void); > > -- > 1.7.4.1
Any comments about this patch? Best Regards, Neil Zhang
